Seer IV. 7. ANIMAL CAUSATION. 33 



a greater or lefs quantity of contraction, if it be 

 perceived at all, produces pain ; thefe conftitute 

 fenfation. 



VI. A certain quantity of fenfation produces de- 

 lire or averfion ; thefe conftitute volition. 



VII. All animal motions which have occurred at 

 the fame time, or in immediate fucceffion, become 

 fo connected, that when one of them is reproduced, 

 the other has a tendency to accompany or fucceed it. 

 When fibrous contractions fucceed or accompany 

 other fibrous contractions, the connection is termed 

 affociation ; when fibrous contractions fucceed fen- 

 forial motions, the connection is termed caufation ; 

 when fibrous and fenforial motions reciprocally in- 

 troduce each other, it is termed catenation of ani- 

 mal motions. All thefe connections arefaid to be pro- 

 duced by habit, that is, by frequent repetition. Thefe 

 laws of animal caufation will be evinced by numerous 

 facts, which occur in our daily exertions; and will 

 afterwards be employed to explain the more recon- 

 dite phaenomena of the production, growth, dif- 

 cafes, and decay of the animal fyftem. 



SECT, 



